The goal of this research is to further our understanding of masculine copulatory behavior in general, and the ejaculation response of laboratory rats in particular. Three major problems addressed: the effect of frustration and other noncopulatory sources of arousal on ejaculatory potential; the role of the amygdala in processing copulatory input; and the conditions under which the ejaculatory potential of female rats, never treated with androgen, may be expressed. The studies will therefore offer neural, endocrine, and psychological perspectives on a key sexually dimorphic behavior. BIBLIOGRAPHIC REFERENCES: Emery, D. E. and Sachs, B. D. Ejaculatory pattern in female rats without androgen treatment. Science, 1975, 190, 484-486. Harris, V. S. and Sachs, B. D. Copulatory behavior in male rats following amygdaloid lesions. Brain Research, 1975, 86, 514-518.